He values the venal value or the rental value of properties (buildings, business, premises, etc).
Estate expertise concerns two sorts of activities :
Business man for whom work consists in purchasing buildings for his personal account, to resell them intending to produce profits. This business doesn’t have specific rules and doesn’t offer guarantees such as the estate agent , but it has a specific tax system . However many estate merchants buy, then restore to improve buildings, in order to resell them renovated.